Tiopronin

Tiopronin

Names
IUPAC name 2-(2-sulfanylpropanoylamino)acetic acid
Other names 2-mercaptopropionylglycine Acadione Thiola
Identifiers
CAS Number	1953-02-2 Y 29335-92-0 R Y
3D model (JSmol)	Interactive image Interactive image
Beilstein Reference	1859822
ChemSpider	5283 Y 180938 R Y 643292 S Y
ECHA InfoCard	100.016.163
EC Number	217-778-4
KEGG	D01430 Y
MeSH	Tiopronin
PubChem CID	5483 208825 R 736152 S
RTECS number	MC0596500
UNII	C5W04GO61S Y
InChI InChI=1S/C5H9NO3S/c1-3(10)5(9)6-2-4(7)8/h3,10H,2H2,1H3,(H,6,9)(H,7,8) Y Key: YTGJWQPHMWSCST-UHFFFAOYSA-N Y
SMILES CC(S)c(:[o]):[nH]Cc(:[o]):[oH] CC(S)C(=O)NCC(O)=O
Properties
Chemical formula	C5H9NO3S
Molar mass	163.19 g·mol−1
Appearance	White, opaque crystals
Melting point	93 to 98 °C (199 to 208 °F; 366 to 371 K)
log P	−0.674
Acidity (pKa)	3.356
Basicity (pKb)	10.641
Pharmacology
ATC code	G04BX16 (WHO)
Pregnancy category	US: C (Risk not ruled out)
Legal status	US: ℞-only
Hazards
GHS pictograms
GHS signal word	WARNING
GHS hazard statements	H302
Lethal dose or concentration (LD, LC):
LD50 (median dose)	1,300 mg kg−1(oral, rat)
Related compounds
Related alkanoic acids	Acetylcysteine Glycylglycine Iminodiacetic acid Nitrilotriacetic acid N-Oxalylglycine Bucillamine Oxalyldiaminopropionic acid gamma-Glutamylcysteine
Related compounds	N-Acetylglycinamide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Y  (what is YN ?)
Infobox references

Tiopronin (trade name Thiola) is a prescription thiol drug used to control the rate of cystine precipitation and excretion in the disease cystinuria. Due to the rarity of the disorder, tiopronin falls under the classification of an orphan drug. It is somewhat similar to penicillamine in both chemistry and pharmacology.

Tiopronin is used primarily for cystinuria and is well known in the cystinuric community. Depending on the severity of a person's cystinuria, tiopronin may be taken for life, possibly starting in early childhood. The drug works by reacting with urinary cysteine to form a more soluble, disulfide linked, tiopronin-cysteine complex.

It may also be used for Wilson's disease (an overload of copper in the body), and has also been investigated for the treatment of arthritis, though tiopronin is not an anti-inflammatory.

Tiopronin is also sometimes used as a stabilizing agent for metal nanoparticles. The thiol group binds to the nanoparticles, preventing coagulation.

Tiopronin may present a variety of side effects, which are broadly similar to those of D-penicillamine and other compounds containing active sulfhydryl groups. Its pharmokinetics have been studied.

In the U.S., the drug was marketed by Mission Pharmacal at $1.50 per pill, but the rights were bought by Retrophin, owned by Martin Shkreli, and the price increased to $30 per pill for a 100mg capsule. A potential alternative in treatment and costs has arisen with the drug 'Bucillamine'. There is now a low-cost alternative available from Imprimis Pharmaceuticals Inc., Tiopronin Delayed Release, at $7.68 for 100mg.